Kenneth L Ward

US Patent:

54940320, Feb 27, 1996

Filed:

May 23, 1994

Appl. No.:

8/247297

Inventors:

Mark R. Robinson - Albuquerque NM
David M. Haaland - Albuquerque NM
Kenneth J. Ward - Madison WI

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

A61B 500

US Classification:

128633

Abstract:

With the crude instrumentation now in use to continuously monitor the status of the fetus at delivery, the obstetrician and labor room staff not only over-recognize the possibility of fetal distress with the resultant rise in operative deliveries, but at times do not identify fetal distress which may result in preventable fetal neurological harm. The invention, which addresses these two basic problems, comprises a method and apparatus for non-invasive determination of blood oxygen saturation in the fetus. The apparatus includes a multiple frequency light source which is coupled to an optical fiber. The output of the fiber is used to illuminate blood containing tissue of the fetus. In the preferred embodiment, the reflected light is transmitted back to the apparatus where the light intensities are simultaneously detected at multiple frequencies. The resulting spectrum is then analyzed for determination of oxygen saturation. The analysis method uses multivariate calibration techniques that compensate for nonlinear spectral response, model interfering spectral responses and detect outlier data with high sensitivity.

US Patent:

49755811, Dec 4, 1990

Filed:

Jun 21, 1989

Appl. No.:

7/369217

Inventors:

Mark R. Robinson - Albuquerque NM
Kenneth J. Ward - Albuquerque NM
Robert P. Eaton - Albuquerque NM
David M. Haaland - Albuquerque NM

Assignee:

University of New Mexico - Albuquerque NM

International Classification:

G01N 2135

US Classification:

250339

Abstract:

The characteristics of a biological fluid sample having an analyte are determined from a model constructed from plural known biological fluid samples. The model is a function of the concentration of materials in the known fluid samples as a function of absorption of wideband infrared energy. The wideband infrared energy is coupled to the analyte containing sample so there is differential absorption of the infrared energy as a function of the wavelength of the wideband infrared energy incident on the analyte containing sample. The differential absorption causes intensity variations of the infrared energy incident on the analyte containing sample as a function of sample wavelength of the energy, and concentration of the unknown analyte is determined from the thus-derived intensity variations of the infrared energy as a function of wavelength from the model absorption versus wavelength function.